1. Field of the Invention
This invention relates generally to an integrated automatic focusing and exposure control apparatus and, more particularly, to an integrated focusing and exposure control apparatus comprising a combination latch and actuator mechanism for latching the exposure control apparatus and actuating the focusing apparatus.
2. Description of the Prior Art
Ultrasonic ranging systems are well known for cameras, and in each of the systems ultrasonic energy is transmitted toward a subject to be photographed and the subject reflects the ultrasonic energy back to the camera. Characteristics of the transmitted and received signals may be compared to derive a control signal representative of the subject distance. The control signal can be thereafter used to drive the lens mount of the camera to a position corresponding to the subject distance whereby the subject will be in focus.
U.S. patent application Ser. No. 840,802 entitled "Ultrasonic Ranging System for a Camera" by J. Muggli filed in common assignment herewith provides an ultrasonic ranging system for a camera having a lens mount movable to a position at which a subject being photographed is in focus. The system includes an ultrasonic transducer that responds to a keying pulse by transmitting a relatively short burst of frequency modulated ultrasonic energy and a synchronized receiver for processing an echo signal produced by the transducer upon receipt of an echo upon a predetermined time interval. The receiver produces a range signal with a characteristic related to the distance of a subject being photographed from the camera. The range signal representing the subject distance may thereafter be used in a manner as is more fully disclosed in U.S. patent application Ser. No. 916,114 entitled "Automatic Focusing Camera", filed June 16, 1978 in common assignment herewith to control a gated pulse generator in a nonlinear manner such that the latter produces a train of pulses whose number is representative of the actual position of the lens mount at which the subject will be in focus, and includes a focusing mechanism having means responsive to the pulse produced by the pulse generator means for displacing the lens mount to the proper position. Such systems are complex and expensive since the range signal must be utilized to control a gated pulse in a nonlinear manner to produce a train of pulses whose number is representative of the actual position of a lens mount. The focusing mechanism must then embody a servo-mechanism to respond to the pulses produced by the pulse generator in order to mechanically displace the lens mount to the proper axial position thereby further contributing to the complex nature of such auto focus arrangements.
A simplified automatic sonar controlled focusing apparatus wherein the objective lens movement occurs in an elapsed time interval which is directly proportional to the elapsed time interval between which the sonar ranging signal is transmitted and thereafter received subsequent to being reflected by the photographic subject as is more fully described in U.S. patent application Ser. No. 919,084, entitled "Sonar Controlled Lens Focus Apparatus", by B. Johnson et al., filed June 26, 1978 in common assignment herewith. The preferred objective lens arrangement comprises a plurality of lens elements mounted for displacement between a plurality of focal positions by a lens holding disc member disposed for rotation about a fixed center axis. The plurality of lens elements are disposed on the lens holding disc member in circumferentially spaced-apart relation with respect to each other about the center axis. Exposure control is provided by a scanning shutter blade arrangement including a pivotally disposed walking beam for imparting counter reciprocal sliding movement to the shutter blade elements. The walking beam is pivotally disposed to impact upon an actuator member which, in turn, operates by way of a torsion spring to impact upon the lens holding disc member and thereby rotate the lens holding member so as to sequentially move each of the lens elements into the focal position. The shutter blade arrangement also includes a latch mechanism for holding the shutter blade elements in the scene light blocking position prior and subsequent to the exposure interval. Although the aforementioned focusing and exposure control apparatus functions in an entirely satisfactory manner, it is nevertheless advantageous to integrate and simplify the aforementioned focusing and exposure control apparatus to the fullest extent possible. Therefore it is a primary object of this invention to provide a simpler and better integrated focusing and exposure control apparatus of the aforementioned type.
It is a further object of this invention to provide a simple and integrated focusing and exposure control apparatus including a combination latch and actuator member for latching the exposure control apparatus and actuating the focusing apparatus.